Heavy products such as outboard boat motors are generally packaged in a container for handling and shipping purposes. Often these motors weigh several hundred pounds. The containers for such heavy products must include adequate strength to permit handling of the packaged motors with fork lift trucks or clamp trucks. Manufacturers produce large quantities in assembly line manner and must be able to stack the packaged motors up to eight or more units high in their warehouse. The cost of warehousing is expensive and normally such warehouses are built with very high ceiling heights to increase the product storage per cubic foot of space. Therefore, such containers must be adequate in compression or stacking strength to safely allow the maximum number of units in a stack.
Another substantial cost incurred by manufacturers of outboard boat motors is the freight cost associated with shipping the motors from the manufacturer's plant to the distributor or dealer. Due to the size and shape of the motors, it is necessary that as many packaged motors as possible be loaded into a van or trailer to minimize the freight cost per unit. This requires that the container be of minimal external dimensions given the physical dimensions of the particular motor and the required internal container dimensions to accommodate some movement of the motor in the container. The container must have sufficient vertical and horizontal stacking strength. Vertical strength allows the packaged motors to be stacked to the maximum height available in the shipping trailer. Adequate lateral strength enables the container to resist sideways collapse during stacked shipment. The uppermost units in a stack exert lateral stresses on the lower containers due to the stopping and starting horizontal forces incurred during transit.
An outboard motor presents a very difficult packaging problem for several reasons. Such motors are of non-symmetrical construction in both longitudinal and traverse dimensions and in weight distribution. The engine, or powerhead, is the largest and heaviest component of the motor and is located at an upper end of the motor. The powerhead is connected through an adaptor casting to the gearcase which is a relatively long and lightweight semi-rectangular section that houses the drive shaft and gearing. The propeller shaft connects to the end of the drive shaft through another gearing mechanism. A lower rudder-shaped extension called a skeg is attached at the lower end of the motor. A mounting bracket, or stern bracket, connects to the powerhead near the junction of the powerhead and the gearcase. The stern bracket mounts the outboard motor to the stern of a boat. The stern bracket incorporates a pivot mechanism which allows the motor to pivot in the horizontal plane for steering purposes. The stern bracket also incorporates a tilting mechanism which allows the motor to be tilted in the vertical plane to adjust for different weight loading distributions in the boat, speeds and planing factors.
Typically, the powerhead is enclosed by a fiberglass hood or cover. Very close tolerances exist between certain components of the powerhead and the motor cover. Such components in the powerhead often have relatively sharp and hard surfaces and can damage the fiberglass motor cover if the motor cover is forced into them by external shocks incurred during handling and transit. Also, the powerhead itself is normally mounted to the gearcase section through the adaptor casting with rubber shock absorbing motor mounts. These mounts prevent excess vibration when the motor is in operation, but they allow some internal movement of the motor inside the motor cover. This internal movement can crack the motor cover in cases of rough handling or mishandling during transit.
For the several reasons outlined above, it is advantageous to support the motor by its stern bracket in a shipping container and not by the external surfaces of the motor cover. The motor cover and powerhead must be allowed to move in unison when subjected to external handling and shipping shock forces. This movement reduces the possibility of the engine components damaging the motor cover are reduced. For example, motor covers are expensive, typically costing several hundred dollars, and damage to them in handling and shipment are of major concern to the outboard motor manufacturer.
Most outboard motor manufacturers have rigid testing requirements for their shipping containers. These manufacturers have found through actual shipping experience that often the motors are mishandled in warehousing and transit. Motors are occasionally dropped by fork or clamp truck operators in handling and stacking. Also, if proper loading is not accomplished in truck or rail car shipment, the stacked containers can shift and fall. Many boat dealers do not have adequate loading docks or material handling equipment to properly unload their motors from the freight hauler's trailer. In these cases, the packaged motors are manually "walked" or pushed to the back of the trailer and lowered down to ground level by hand. Dropping of the container can occur in these cases with resultant damage to the motors if the container is of insufficient strength.
Because such outboard motors may cost many thousands of dollars, the protection of motors during handling, warehousing, and shipping is of primary importance to manufacturers. A container for shipping outboard boat motors must be externally strong and rigid enough to maximize warehouse space utilization through multiple stacking. The container must be strong enough to resist collapse during stacked shipment and to protect the motor in cases of mishandling, such as dropping from trailers during unloading. The container must be of minimal external dimensions to allow the greatest number of units to be loaded into a trailer for shipment. Yet the must have adequate internal shock absorption and clearance between the motor cover and other components and the container walls to prevent damage to the motor from external handling and shipping shock forces.
A further requirement of such outboard motor containers is that the container should facilitate easy and efficient packaging of the motor on the assembly lines. This mandates that the container be comprised of as few component parts as possible and that minimal labor is required to set up the package and insert the motor. Often the assembly lines run at high rates, up to 500 or more motors per day per line, and packaging simplicity is of major importance. Such containers must be designed to be shipped to the motor manufacturers from the container manufacturer in a collapsed or "knocked-down" state. This minimizes the freight costs associated with shipping the containers to the motor manufacturer. Also, and warehousing container space requirements and on-line container space requirements at the manufacturers will be minimized.
Outboard boat motors are shipped in either a vertical or horizontal orientation. In the vertical orientation, the outboard motor is normally loaded into the shipping container with the powerhead down so as to keep the center of gravity as low as possible in the container to resist tipping over during handling and shipment. In such a vertical pack, the motor is secured to a motor frame or crossbar by bolting through the stern bracket in a manner similar to attaching the motor to the stern of a boat. Typically such containers have vertical supports to provide stacking strength, as well as top and bottom frames to allow for forklift and clamp truck handling.
In the horizontal shipping orientation, the motor is placed horizontal, or nearly so, onto a base or skid assembly which allows fork lift entry for handling. Normally the motor is attached to a cross bar that simulates the stern of a boat and some means are used to secure the cross bar to the base. Care must be taken to prevent the motor from pivoting or turning about its swivel bracket which is the mechanism attached to the stern bracket that allows the motor to turn from side to side in steering the boat. If some method of restraining the motor is not provided for, it can swivel and contact the container walls during handling and shipment, possibly damaging the motor and container. In a mishandling situation such as a drop, the container itself must withstand the shock and prevent the motor from swiveling or torquing to the degree that it comes in contact with the container wall and the floor, fork lift mast, or other hard surfaces beyond the container walls.
In the horizontal container, a box surrounds the motor and attaches to the base. As discussed above, the box must be of sufficient strength to allow for warehouse stacking up to eight or more units high and for stacked truck or rail car shipment. In addition the box must have vertical strength through to the top surface so that misalignment in stacking will not result in the upper units falling through and crushing the lower units in a stack. As those of ordinary skill will understand, a box or container achieves most of its stacking strength at the corners where the right angles between the sides and end walls of the box join. If such a box is to be further reinforced by either internal or external vertical posts or columns, either mechanically attached to the walls of the box or simply designed to be placed or restrained next to the walls in some manner, said columns or posts are almost universally located at or as near as possible to the corners of the box. This is so that the right angles formed at the corners will provide the maximum vertical stabilization to the posts, which are the major load bearing members in warehouse or trailer stacking.
In freight shipments of less than full truckloads, freight carriers will often place other packages of various sizes and weights on one another to maximize revenue per loaded mile. The top of the box must therefore have sufficient bracing or strength to withstand small, heavy packages centerloaded onto it, away from the corners.
The base of such horizontal containers must be stiff and rigid enough to allow the packaged motors to be picked up by fork lift trucks while stacked several units high. This is necessary to facilitate and minimize truck loading time and handling time from the assembly lines to the warehouse. Many manufacturers use clamp, or squeeze trucks instead of fork lift trucks. Clamp trucks employ hydraulically operated platens that exert inward pressure onto the container walls, enabling the mast cylinder of the clamp truck to raise the package for loading or stacking. In such cases, the container must have adequate strength across its length and width to withstand the clamp pressure. A container that crushes in clamp handling can result in damage to the motor as well as becoming a safety hazard if the container slips from the platens during handling or stacking.
Containers known to be used in shipping outboard boat motors horizontally use wood bases with corrugated paperboard upper boxes. A plurality of corrugated paperboard or solid-fibre posts insert into the container to provide vertical and horizontal stacking and clamp strength. Such containers are cumbersome and slow to pack due to the many separate component parts. The corrugated upper box and posts may have adequate strength initially, but since corrugated paperboard is not resilient, crushing and loss of strength occur and increase with each handling step during the distribution cycle from manufacturers to distributors to dealer. Additionally, corrugated paperboard will lose up to 50% of its strength in conditions of high heat and humidity. Many shipments of outboard motors involve long periods of storage in closed vans or in warehouses where humidity levels can be 90% or higher. In such cases, previous containers grouped in stacks in warehouses have been known to fall with resultant damage costs and safety hazards. Also, due to the non-resilient nature of corrugated paperboard, the internal restraining posts and other inserted supports tend to weaken with the repetitive handling and shipping shocks. Handling and shipping applies forces to the posts and supports which loosen and allow the motor excessive movement within the container. Subsequent mishandling and drops can result in the momentum of the motor carrying it past the container wall into the floor, ground, lift truck mast or trailer wall, with damage occurring.
Some small outboard motors are known to have been shipped in styrofoam molded forms encased in a corrugated paperboard outer box. In these packs, the motor cover itself is the bearing surface. This is not a preferred method for the reasons mentioned above, and specifically because the powerhead can move on its rubber motor mounts during a drop or other mishandling and contact the rigidly restrained motor cover. Styrofoam also is becoming a disposal problem in many areas of the world, and the use of it is not desirable in such packaging for this reason as well. In addition, the foam packs do not have adequate rigidity in stacking or clamp handling.
Accordingly, there is a need in the art for an improved container for storing and shipping outboard motors.